کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9566770 | 1388371 | 2005 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Crystallinity effect in the textural properties of titania-TPA catalysts
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
Catalysts based in titania mixed with tungstophosphoric acid (TPA), H3PW12O40, in various proportions (1, 15, 25 and 50 wt%) were obtained by the sol-gel method. The gels were prepared by hydrolysis and gellation of titanium n-butoxide with a TPA solution, using HNO3 as a catalyst to obtain a pH 3. Fresh samples were thermally treated from 100 to 800 °C, in a stepwise increment of 100 °C during 20 h per step. Specific surface areas were calculated by the BET method from the nitrogen adsorption isotherms; it was found that the surface area increased with TPA content. The crystallization behavior was followed by powder X-ray diffraction. Crystallite size measurements showed that anatase remains nanocrystalline in the studied temperature range. From the X-ray data, it was clear that below 700 °C TPA is highly dispersed in an amorphous state.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 252, Issue 3, 31 October 2005, Pages 853-857
Journal: Applied Surface Science - Volume 252, Issue 3, 31 October 2005, Pages 853-857
نویسندگان
E. Ortiz-Islas, T. Lopez, R. Gomez, M. Picquart, D.H. Aguilar, P. Quintana,